Leukocyte filter unit

Abstract

A method for removing leukocytes from a leukocyte-containing suspension comprising passing said suspension through a filter including a nitrocellulose membrane having a pore size of 5-15 μm.

We claim: 
     
       1. A filter unit for a blood-derived suspension containing both leukocytes and erythrocytes, said unit having a filter for removing leukocytes from said suspension, said filter including a plurality of layers all capable of passing erythrocytes, at least two of said layers being nitrocellulose membranes, wherein said nitrocellulose membranes include at least one nitrocellulose membrane having a pore size of 5-15 microns blocking said leukocytes while passing said erythrocytes and at least two of said layers being non-woven fibrous media. 
     
     
       2. A filter unit according to claim 1, and wherein at least one of said plurality of layers comprises a non-woven polymer fiber which constitutes a pre-filter. 
     
     
       3. A filter unit according to claim 2, and wherein one of said plurality of layers includes a plurality of nitrocellulose membranes interspersed by non-woven polymer fiber spacers. 
     
     
       4. A filter unit according to claim 3, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer. 
     
     
       5. A filter unit according to claim 2, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer. 
     
     
       6. A filter unit according to claim 1, and wherein one of said plurality of layers includes a plurality of nitrocellulose membranes interspersed by non-woven polymer fiber spacers. 
     
     
       7. A filter unit according to claim 6, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer. 
     
     
       8. A filter unit according to claim 1, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer.